Acquisition of the MicroCal Auto-iTC System will support NIH-funded projects from PIs across the UAB campus and Emory who require a quantitative and complete thermodynamic evaluation of the molecular interactions of biological macromolecules. Four major and 8 minor users who represent 7 departments and 4 schools and an additional 7 minor users with pending NIH grants or other support representing 3 departments and 2 schools will be served by this instrument. Isothermal titration calorimetry (ITC) has been successfully used in many applications to study a diverse range of systems including those proposed by our user group as described here, e.g., the interactions of small molecules, proteins, antibodies, nucleic acids and lipids;the effects of mutations and molecular structure changes on binding mechanism and the effect of binding on bound structure. ITC is unique in its ability to quantitate the affinity, stoichiometry and the thermodynamic parameters of binding in a single experiment (?H, ?S, ?G in one experiment;?Cp in ~3 experiments). There simply is no other technique that can not provide the breadth of information in so little time nor with so little material for interactions in solution and furthermore no extrinsic labeling is required. The MicroCal Auto-iTC200 System is the newest generation ITC offered by MicroCal and it is unrivaled with respect to its sensitivity and automation;in fact, there is no other robotic ITC commercially available and this feature makes it ideal for a multi-user core facility. The PI, Dr. Brouillette, and her senior research associate, Dr. Protassevitch, each have about 30 years of calorimetry experience. They currently manage a biomolecular analysis core within UAB's Comprehensive Cancer Facility which offers a Biacore2000 and a MicroCal automated capDSC to users. This functioning core, with current users across campus, is physically housed within the Center for Biophysical Sciences and Engineering (CBSE). If the present grant is funded, the AutoiTC200 System will also be housed and administered through this existing core facility. Infrastructure support and space is provided by the CBSE. A reasonable user fee will be charged to cover routine maintenance and oversight by the experienced personnel. Additional assistance will be provided at an additional cost. As an example of the breadth of biomedical research which would be supported by this instrument, the NIH grant titles for the four major users are given: NIAID U01 "Discovery and Preclinical Development of Drugs for Anthrax, Plague and Tularemia;" NIDCR R01 "Determination of the SAG Binding Motif on Agl/II of Streptococcous Mutans;" NCI P50 project 1 "SPORE in Breast Cancer;" NIGMS R01 "Structural and Functional Studies for Mitochondrial Protein Translocations;" and NIDDK "Structural and Functional Studies of Hsp40."